1. Field of the Invention
The subject matter of the present disclosure generally relates to gas turbine engines and more particularly to spacers used in turbine fan blades.
2. Description of Related Art
Gas turbine engines use a series of blades to compress input gases or to extract energy from exhaust gases. The front-most or leading edge blades are often subjected to unwanted contact, particularly collision with birds. In most cases bird strikes cause little or no damage, but may result in a dented or bent blade. However, bird strikes are also known to have caused significant damage, perhaps the most famous of which is the US Airways Flight 1549 that made a water landing on the Hudson River when bird strikes caused shut down of both of the plane's two engines.
Designing fan blades for bird strike scenarios is challenging for at least two reasons. First, the fan blade must perform in a desired manner during the actual bird strike at the impact site. Second, the fan blade is subject to high bending and twisting loads near the fan blade attachment location in response to the impact. The attachment locations are typically provided by hub slots that receive a root at a base of each fan blade. The root loads are especially damaging if the fan blade is rigidly constrained.
Spacers may be used between the fan blades at the hub to act as a fulcrum against which the fan blades can bend and/or twist under loads. These spacers are rigid to provide support to the blade after assembly.
Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for spacers with improved impact robustness. There also remains a need in the art for such systems and methods that are easy to make and use. The present disclosure provides a solution for these problems.